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Liang SY, Li LH, Ling MX, Mo L, Huang LM, Ruan LR, Shang CH. Combined effects of nitrogen limitation and overexpression of malic enzyme gene on lipid accumulation in Dunaliella parva. BIORESOURCE TECHNOLOGY 2024; 410:131291. [PMID: 39153698 DOI: 10.1016/j.biortech.2024.131291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 08/08/2024] [Accepted: 08/14/2024] [Indexed: 08/19/2024]
Abstract
Overexpression of Dunaliella parva (D. parva) malic enzyme (ME) gene (DpME) significantly increased DpME expression and ME enzyme activity in transgenic D. parva. Nitrogen limitation had an inhibitory effect on protein content, and DpME overexpression could improve protein content. Nitrogen limitation increased carbohydrate content, and Dunaliella parva overexpressing malic enzyme gene under nitrogen limitation (DpME-N-) group showed the lowest starch content among all groups. Dunaliella parva overexpressing malic enzyme gene under nitrogen sufficient condition (DpME) and DpME-N- groups showed considerably high mRNA levels of DpME. ME activity was significantly enhanced by DpME overexpression, and nitrogen limitation caused a smaller increase. DpME overexpression and nitrogen limitation obviously enhanced lipid accumulation, and DpME overexpression had more obvious effect. Compared with control (wild type), lipid content (68.97%) obviously increased in DpME-N- group. This study indicated that the combination of DpME overexpression and nitrogen limitation was favorable to the production of microalgae biodiesel.
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Affiliation(s)
- Shi-Yu Liang
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education & Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin (Guangxi Normal University), Guilin, Guangxi 541006, China
| | - Li-Hua Li
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education & Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin (Guangxi Normal University), Guilin, Guangxi 541006, China
| | - Meng-Xiang Ling
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education & Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin (Guangxi Normal University), Guilin, Guangxi 541006, China
| | - Lei Mo
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education & Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin (Guangxi Normal University), Guilin, Guangxi 541006, China
| | - Li-Mei Huang
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education & Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin (Guangxi Normal University), Guilin, Guangxi 541006, China
| | - Ling-Ru Ruan
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education & Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin (Guangxi Normal University), Guilin, Guangxi 541006, China
| | - Chang-Hua Shang
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education & Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin (Guangxi Normal University), Guilin, Guangxi 541006, China.
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Govta N, Fatiukha A, Govta L, Pozniak C, Distelfeld A, Fahima T, Beckles DM, Krugman T. Nitrogen deficiency tolerance conferred by introgression of a QTL derived from wild emmer into bread wheat. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2024; 137:187. [PMID: 39020219 PMCID: PMC11255033 DOI: 10.1007/s00122-024-04692-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 07/04/2024] [Indexed: 07/19/2024]
Abstract
KEY MESSAGE Genetic dissection of a QTL from wild emmer wheat, QGpc.huj.uh-5B.2, introgressed into bread wheat, identified candidate genes associated with tolerance to nitrogen deficiency, and potentially useful for improving nitrogen-use efficiency. Nitrogen (N) is an important macronutrient critical to wheat growth and development; its deficiency is one of the main factors causing reductions in grain yield and quality. N availability is significantly affected by drought or flooding, that are dependent on additional factors including soil type or duration and severity of stress. In a previous study, we identified a high grain protein content QTL (QGpc.huj.uh-5B.2) derived from the 5B chromosome of wild emmer wheat, that showed a higher proportion of explained variation under water-stress conditions. We hypothesized that this QTL is associated with tolerance to N deficiency as a possible mechanism underlying the higher effect under stress. To validate this hypothesis, we introgressed the QTL into the elite bread wheat var. Ruta, and showed that under N-deficient field conditions the introgression IL99 had a 33% increase in GPC (p < 0.05) compared to the recipient parent. Furthermore, evaluation of IL99 response to severe N deficiency (10% N) for 14 days, applied using a semi-hydroponic system under controlled conditions, confirmed its tolerance to N deficiency. Fine-mapping of the QTL resulted in 26 homozygous near-isogenic lines (BC4F5) segregating to N-deficiency tolerance. The QTL was delimited from - 28.28 to - 1.29 Mb and included 13 candidate genes, most associated with N-stress response, N transport, and abiotic stress responses. These genes may improve N-use efficiency under severely N-deficient environments. Our study demonstrates the importance of WEW as a source of novel candidate genes for sustainable improvement in tolerance to N deficiency in wheat.
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Affiliation(s)
- Nikolai Govta
- Wild Cereal Gene Bank, Institute of Evolution, University of Haifa, Abba Khoushy Ave 199, 3498838, Haifa, Israel
- Department of Evolutionary and Environmental Biology, University of Haifa, Abba Khoushy Ave 199, 3498838, Haifa, Israel
| | - Andrii Fatiukha
- Department of Evolutionary and Environmental Biology, University of Haifa, Abba Khoushy Ave 199, 3498838, Haifa, Israel
- Crop Development Centre and Department of Plant Sciences, University of Saskatchewan, Saskatoon, Canada
| | - Liubov Govta
- Department of Evolutionary and Environmental Biology, University of Haifa, Abba Khoushy Ave 199, 3498838, Haifa, Israel
| | - Curtis Pozniak
- Crop Development Centre and Department of Plant Sciences, University of Saskatchewan, Saskatoon, Canada
| | - Assaf Distelfeld
- Department of Evolutionary and Environmental Biology, University of Haifa, Abba Khoushy Ave 199, 3498838, Haifa, Israel
| | - Tzion Fahima
- Department of Evolutionary and Environmental Biology, University of Haifa, Abba Khoushy Ave 199, 3498838, Haifa, Israel
| | - Diane M Beckles
- Department of Plant Sciences, University of California, Davis, CA, 95616, USA
| | - Tamar Krugman
- Wild Cereal Gene Bank, Institute of Evolution, University of Haifa, Abba Khoushy Ave 199, 3498838, Haifa, Israel.
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Liang X, Huang L, Ling M, Li L, Ruan L, Shang C. The effect of PK gene overexpression on content and antioxidant properties of carotenoids in marine microalga Dunaliella parva. Gene 2024; 898:148120. [PMID: 38163626 DOI: 10.1016/j.gene.2023.148120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/28/2023] [Accepted: 12/29/2023] [Indexed: 01/03/2024]
Abstract
Dunaliella parva can extensively accumulate carotenoids, which is a promising raw material for carotenoids production. Carotenoids have important medicinal value. D. parva is an ideal organism for studying the mechanism of carotenoid synthesis. Our previous study identified a transcription factor DpAP2 which could regulate carotenoid synthesis in D. parva. In addition, DpAP2 could interact with three proteins with different activities (DNA binding transcription factor activity, protein kinase activity, and alpha-D-phosphohexomutase). To investigate the function of PK gene encoding interacting protein of DpAP2 with protein kinase activity in D. parva, PK gene was cloned into vector pBI221-GFP-UbiΩ-CAT and transformed into D. parva in this study. The results showed that overexpression of PK gene enhanced the contents of carotenoids, total sugars, proteins, and antioxidant activities of carotenoid extract such as superoxide radical scavenging activity, reducing power, hydroxyl radical scavenging activity in transgenic D. parva with overexpression of PK gene. This study explored the function of PK gene, and improved the medicinal value of D. parva.
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Affiliation(s)
- Xiuli Liang
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin (Guangxi Normal University), Guilin, Guangxi 541006, China.
| | - Limei Huang
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin (Guangxi Normal University), Guilin, Guangxi 541006, China.
| | - Mengxiang Ling
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin (Guangxi Normal University), Guilin, Guangxi 541006, China.
| | - Lihua Li
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin (Guangxi Normal University), Guilin, Guangxi 541006, China.
| | - Lingru Ruan
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin (Guangxi Normal University), Guilin, Guangxi 541006, China.
| | - Changhua Shang
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin (Guangxi Normal University), Guilin, Guangxi 541006, China.
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Zou Q, Huang L, Gu J, Pang B, Shang C. Physiological changes of microalga Dunaliella parva under the treatment of PEG, CaCl2. PLoS One 2023; 18:e0295973. [PMID: 38100462 PMCID: PMC10723680 DOI: 10.1371/journal.pone.0295973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 11/29/2023] [Indexed: 12/17/2023] Open
Abstract
Carotenoids are antioxidants, which reduce various chronic diseases of human, and have many industrial applications. The halophilic Dunaliella parva (D. parva) is rich in carotenoids. The compounds CaCl2 and PEG are the popular metabolic enhancers. To further enhance carotenogenesis, D. parva was treated with two compounds polyethylene glycol (PEG) and CaCl2. Application of CaCl2 and PEG enhanced the carotenoids contents and the antioxidant activities of carotenoids compared to control group (no treatment of CaCl2 or PEG). The highest carotenoids contents were obtained by treating D. parva with 40 ppm CaCl2 (3.11 mg/g dry weight, DW) and 80 ppm PEG (2.78 mg/g DW) compared with control group (1.96 mg/g DW). When D. parva was treated with 40 ppm CaCl2 and 80 ppm PEG, protein contents reached the highest values (90.28 mg/g DW and 89.57 mg/g DW) compared to that of control group (73.42 mg/g DW). The antioxidant activities of carotenoids samples were determined. Generally, the antioxidant activities of carotenoids from D. parva treated with PEG and CaCl2 were superior to that of control group. The antioxidant activities of carotenoids mainly contained reducing power, hydroxyl radical scavenging activity and superoxide radical scavenging activity. The reducing powers of carotenoids extracts from 20 ppm CaCl2 group (2.07%/mg carotenoids) and 120 ppm PEG group (1.59%/mg carotenoids) were significantly higher than that of control group (<1.25%/mg carotenoids). The superoxide radical scavenging activities of carotenoids extracts from 40 ppm CaCl2 group (70.33%/mg carotenoids) and 80 ppm PEG group (65.94%/mg carotenoids) were significantly higher than that of control group (<55%/mg carotenoids). This paper laid a foundation for massive accumulation of carotenoids in microalga D. parva.
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Affiliation(s)
- Qiman Zou
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Ministry of Education) & Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, Guilin, Guangxi, China
| | - Limei Huang
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Ministry of Education) & Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, Guilin, Guangxi, China
| | - Jinghui Gu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Ministry of Education) & Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, Guilin, Guangxi, China
| | - Bingbing Pang
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Ministry of Education) & Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, Guilin, Guangxi, China
| | - Changhua Shang
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Ministry of Education) & Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, Guilin, Guangxi, China
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Liang MH, Xie SR, Chen HH, Jiang JG. DbMADS regulates carotenoid metabolism by repressing two carotenogenic genes in the green alga Dunaliella sp. FACHB-847. J Cell Physiol 2023; 238:1324-1335. [PMID: 37087727 DOI: 10.1002/jcp.31017] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 03/11/2023] [Accepted: 03/14/2023] [Indexed: 04/24/2023]
Abstract
MADS transcription factors are involved in the regulation of fruit development and carotenoid metabolism in plants. However, whether and how carotenoid accumulation is regulated by algal MADS are largely unknown. In this study, we first used functional complementation to confirm the functional activity of phytoene synthase from the lutein-rich Dunaliella sp. FACHB-847 (DbPSY), the key rate-limiting enzyme in the carotenoid biosynthesis. Promoters of DbPSY and DbLcyB (lycopene β-cyclase) possessed multiple cis-acting elements such as light-, UV-B-, dehydration-, anaerobic-, and salt-responsive elements, W-box, and C-A-rich-G-box (MADS-box). Meanwhile, we isolated one nucleus-localized MADS transcription factor (DbMADS), belonging to type I MADS gene. Three carotenogenic genes, DbPSY, DbLcyB, and DbBCH (β-carotene hydroxylase) genes were upregulated at later stages, which was well correlated with the carotenoid accumulation. In contrast, DbMADS gene was highly expressed at lag phase with low carotenoid accumulation. Yeast one-hybrid assay and dual-luciferase reporter assay demonstrated that DbMADS could directly bind to the promoters of two carotenogenic genes, DbPSY and DbLcyB, and repress their transcriptions. This study suggested that DbMADS may act as a negative regulator of carotenoid biosynthesis by repressing DbPSY and DbLcyB at the lag phase, which provide new insights into the regulatory mechanisms of carotenoid metabolism in Dunaliella.
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Affiliation(s)
- Ming-Hua Liang
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Institute of Ecological Science, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Shan-Rong Xie
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Hao-Hong Chen
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Jian-Guo Jiang
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
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Optimization of Extraction Conditions of Carotenoids from Dunaliella parva by Response Surface Methodology. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27041444. [PMID: 35209233 PMCID: PMC8924885 DOI: 10.3390/molecules27041444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 11/17/2022]
Abstract
Extraction conditions can exert a remarkable influence on extraction efficiency. The aim of this study was to improve the extraction efficiency of carotenoids from Dunaliella parva (D. parva). Dimethyl sulfoxide (DMSO) and 95% ethanol were used as the extraction solvents. The extraction time, extraction temperature and the proportions of mixed solvent were taken as influencing factors, and the experimental scheme was determined by Central Composite Design (CCD) of Design Expert 10.0.4.0 to optimize the extraction process of carotenoids from D. parva. The absorbance values of the extract at 665 nm, 649 nm and 480 nm were determined by a microplate spectrophotometer, and the extraction efficiency of carotenoids was calculated. Analyses of the model fitting degree, variance and interaction term 3D surface were performed by response surface analysis. The optimal extraction conditions were as follows: extraction time of 20 min, extraction temperature of 40 °C, and a mixed solvent ratio (DMSO: 95% ethanol) of 3.64:1. Under the optimal conditions, the actual extraction efficiency of carotenoids was 0.0464%, which was increased by 18.19% (the initial extraction efficiency of 0.03926%) with a lower extraction temperature (i.e., lower energy consumption) compared to the standard protocol.
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Ismaiel MMS, El-Ayouty YM, Fathey HA. Disparity of the carotenoids antioxidant properties of wild-type and D-PSY-transgenic Dunaliella parva strains under three environmental stresses. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2021; 27:2151-2163. [PMID: 34744358 PMCID: PMC8526634 DOI: 10.1007/s12298-021-01077-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/09/2021] [Accepted: 09/19/2021] [Indexed: 06/13/2023]
Abstract
UNLABELLED Two strains of the halophilic alga Dunaliella parva, a wild type (WT) and a transgenic strain (D-PSY) containing an exogenous phytoene synthase gene (PSY), were used to investigate the growth, carotenoid accumulation, and carotenoid antioxidant properties under nitrogen starvation, cobalt and biochar treatments. D-PSY had higher carotenoid content (1.8 times) compared to the WT. The applied stressors stimulated the carotenoid content of both WT and D-PSY especially. The carotenoids were assayed for the potential antioxidant activities by five different assays. Generally, the antioxidant activities of D-PSY carotenoids were superior to that of WT. The biochar and nitrogen treatments generally enhanced the antioxidant activities of the carotenoids, whereas cobalt came third in this respect. The D-PSY transgenic algal strain has both high carotenoids content and antioxidant properties which enhanced under the relatively lower concentrations of the applied stressors. The results have shown to lead to an accurate application of the transgenic alga as a source of potent antioxidant compounds. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s12298-021-01077-0.
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Affiliation(s)
- Mostafa M. S. Ismaiel
- Department of Botany and Microbiology, Faculty of Science, Zagazig University, Zagazig, 44519 Egypt
| | - Yassin M. El-Ayouty
- Department of Botany and Microbiology, Faculty of Science, Zagazig University, Zagazig, 44519 Egypt
| | - Hoda A. Fathey
- Department of Botany and Microbiology, Faculty of Science, Zagazig University, Zagazig, 44519 Egypt
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Shaker S, Morowvat MH, Ghasemi Y. Bioinformatics Analysis and Identification of Phytoene Synthase Gene in Microalgae. Recent Pat Biotechnol 2021; 15:216-226. [PMID: 34254932 DOI: 10.2174/1872208315666210712121951] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 03/08/2021] [Accepted: 04/20/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Carotenoids are known as lipophilic secondary metabolites with important biological activities, which are mostly used in the food and pharmaceutical industry. They contribute to the colours of many fruits and flowers. Studies on the biosynthetic pathways of isoprenoids and carotenoids are still scarce, especially in microalgae, and are limited to specific groups Dunaliella spp. In the Chlorophyta taxon of algae, the 2-C-methyl-D-erythritol 4-phosphate/1-deoxy-D-xylulose 5-phosphate (DOXP/MEP) is the synthesis pathway of sterols and carotenoids. OBJECTIVES In this study, we used 12 Psy gene sequences in Dunaliella sp., also Scenedesmus acutus, and Diospyros kaki to investigate a genome-wide search. The results are useful for better identification of carotenoids metabolisms and increasing the production rate of beta-carotene in pharmaceutical, food, and industrial processes. METHODS Phytoene synthase (Psy) from Dunaliella spp. was selected as the first regulatory point in the carotenoids pathway that catalysis the formation of geranylgeranyl pyrophosphate in isoprenoid biosynthesis. Structural, evolutionary, and physics-chemical characteristics were investigated using various bioinformatics tools and computer techniques. Moreover, some recently published patents were also regarded. RESULTS The maximum length of the conserved motif was 5167 bp for Dunaliella. sp. (DQ463306.1), and the smallest length of the conserved motif was 416 bp belong to D. salina (JQ762451.1). The average molecular weight of species was 41820.53 Da. The theoretical pI of species varied from 4.87 to 9.65, indicating vernation in the acidic nature. Two strains of D. bardawil (U91900.1 and EU328287.1) showed just a long-distance relationship with all other Dunaliella strains. Whilst, D. parva displayed the furthest vicinity with all the studied strains. CONCLUSION Our study highlighted the Psy regulatory mechanism as a key factor in the carotenoids pathway to facilitate genetic and metabolic engineering studies. The obtained three-dimensional arrangement of the amino acids revealed the regional structures and folding of the diverse segments of helices, sheets, turns. This information is a key point to unveil the protein's operation mechanism. Besides, we confirmed the suitability of bioinformatic approaches for analysing the gene structures and identifying the new Psy genes in unstudied microalgal strains.
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Affiliation(s)
- Saeedeh Shaker
- Pharmaceutical Sciences Research Centre, Shiraz University of Medical Sciences, P.O. Box 71468-64685, Shiraz, Iran
| | - Mohammad Hossein Morowvat
- Pharmaceutical Sciences Research Centre, Shiraz University of Medical Sciences, P.O. Box 71468-64685, Shiraz, Iran
| | - Younes Ghasemi
- Pharmaceutical Sciences Research Centre, Shiraz University of Medical Sciences, P.O. Box 71468-64685, Shiraz, Iran
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Xi Y, Kong F, Chi Z. ROS Induce β-Carotene Biosynthesis Caused by Changes of Photosynthesis Efficiency and Energy Metabolism in Dunaliella salina Under Stress Conditions. Front Bioeng Biotechnol 2021; 8:613768. [PMID: 33520962 PMCID: PMC7844308 DOI: 10.3389/fbioe.2020.613768] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 11/25/2020] [Indexed: 11/13/2022] Open
Abstract
The unicellular alga Dunaliella salina is regarded as a promising cell factory for the commercial production of β-carotene due to its high yield of carotenoids. However, the underlying mechanism of β-carotene accumulation is still unclear. In this study, the regulatory mechanism of β-carotene accumulation in D. salina under stress conditions was investigated. Our results indicated that there is a significant positive correlation between the cellular ROS level and β-carotene content, and the maximum quantum efficiency (Fv/Fm) of PSII is negatively correlated with β-carotene content under stress conditions. The increase of ROS was found to be coupled with the inhibition of Fv/Fm of PSII in D. salina under stress conditions. Furthermore, transcriptomic analysis of the cells cultivated with H2O2 supplementation showed that the major differentially expressed genes involved in β-carotene metabolism were upregulated, whereas the genes involved in photosynthesis were downregulated. These results indicated that ROS induce β-carotene accumulation in D. salina through fine-tuning genes which were involved in photosynthesis and β-carotene biosynthesis. Our study provided a better understanding of the regulatory mechanism involved in β-carotene accumulation in D. salina, which might be useful for overaccumulation of carotenoids and other valuable compounds in other microalgae.
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Affiliation(s)
- Yimei Xi
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Fantao Kong
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Zhanyou Chi
- School of Bioengineering, Dalian University of Technology, Dalian, China
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Zhu QL, Zheng JL, Liu J. Transcription activation of β-carotene biosynthetic genes at the initial stage of stresses as an indicator of the increased β-carotene accumulation in isolated Dunaliella salina strain GY-H13. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2020; 222:105472. [PMID: 32203794 DOI: 10.1016/j.aquatox.2020.105472] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/10/2020] [Accepted: 03/11/2020] [Indexed: 06/10/2023]
Abstract
β-carotene is an efficient antioxidant and its accumulation is an oxidative response to stressors. Dunaliella salina strain GY-H13 is rich in β-carotene under environmental stresses, which was selected as material to understand the molecular mechanism underlying β-carotene biosynthesis. Seven full length cDNA sequences in β-carotene biosynthesis pathway were cloned, including geranylgeranyl pyrophosphate synthase (GGPS), phytoene synthase (PSY), phytoene desaturase (PDS), 15-cis-zeta-carotene isomerase (ZISO), zeta-carotene desaturase (ZDS), prolycopene isomerase (CRTISO), lycopene beta-cyclase (LCYb). The seven protein sequences from the strain GY-H13 showed the highest similarity with other D. salina strains. Especially, PSY, PDS and LCYb protein sequences shared 100 % identity. Phylogenetic analysis indicated all proteins from GY-H13 firstly clustered with those from other D. salina strains with a bootstrap of 100 %. Multiple alignment indicated several distinct conserved motifs such as aspartate-rich domain (ARD), dinucleotide binding domain (DBD), and carotene binding domain (CBD). These motifs are located near ligand-binding pocket, which may be required for the activity of enzyme. Expression levels of these genes and β-carotene content were measured over 24-h cycle, showing clear daily dynamics. All genes were dramatically up-regulated in the morning but the highest accumulation of β-carotene was observed at noon, suggesting a lag-effect between gene transcription and biological response. Furthermore, the accumulation of β-carotene increased under nitrogen deficiency, Cd exposure and high light and decreased under high salinity in a time-dependent manner. No gene of β-carotene biosynthesis was up-regulated by high salinity while most genes were activated by the other stresses at the beginning stage of exposure. Growth inhibition and oxidative damage were also observed under high salinity. Overall, transcription activation of β-carotene biosynthetic genes at the initial stage of stress exposure is a determinant of the increased accumulation of β-carotene in microalgae, which help their survive under harsh environments. The newly isolated D. salina strain GY-H13 would be a promising microalgae model for investigating the molecular mechanism of stress-induced β-carotene biosynthesis.
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Affiliation(s)
- Qing-Ling Zhu
- Institute of Marine Biology & Pharmacology, Ocean College, Zhejiang University, 1 Zheda Road, Dinghai District, Zhoushan, 316000, Zhejiang, PR China; College of Marine Ocean Science and Technology, Zhejiang Ocean University, Zhoushan, 316022, PR China
| | - Jia-Lang Zheng
- National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, PR China.
| | - Jianhua Liu
- Institute of Marine Biology & Pharmacology, Ocean College, Zhejiang University, 1 Zheda Road, Dinghai District, Zhoushan, 316000, Zhejiang, PR China; College of Marine Ocean Science and Technology, Zhejiang Ocean University, Zhoushan, 316022, PR China.
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Ismaiel MM, El-Ayouty YM, Said AA, Fathey HA. Transformation of Dunaliella parva with PSY gene: Carotenoids show enhanced antioxidant activity under polyethylene glycol and calcium treatments. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2018. [DOI: 10.1016/j.bcab.2018.09.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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